highest peak on the island of New Guinea, in the Sudirman Range, western central highlands. Located in the Indonesian part of New Guinea, known as Irian Jaya, the 16,500-ft (5,030-m) Ngga Palu summit is the highest in the southwestern Pacific and the highest island peak in the world. It marks the terminus of a glacier-capped ridge 8 mi (13 km) long that extends eastward from Ngga Pilimsit (formerly Mt. Idenburg). The ridge, which falls sheer for 10,000 ft on its northern and southern slopes, presents great walls of ice. Although the snowfield of Jaya Peak was reached as early as 1909 by a Dutch explorer, Hendrik A. Lorentz, the peak was not climbed until 1962, by an expedition led by an Austrian mountaineer, Heinrich Harrer.